Epoxy resins for high-performance applications such as aerospace and electrical molding, composites, or laminates have been developed which meet the high-temperature requirements of such applications. For example, epoxy resins based on spirodilactams have high glass transition temperatures (Tg) but suffer from excessively high water absorption for high-performance use. Increasingly, an additional requirement for epoxy resins is a viscosity profile which permits solventless processing of the resins. Epoxy resin compositions based on commercial epoxy resins such as epoxy resins based on diglycidyl ethers of bisphenol-A have low glass transition temperatures.
It is therefore an object of the invention to provide an epoxy resin composition which exhibits a cured Tg above 200.degree. C., low water absorption and processability in the melt useful for laminating, molding and/or compositing.